1 // Copyright 2015 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef ACCELERATED_VIDEO_DECODER_H_ 6 #define ACCELERATED_VIDEO_DECODER_H_ 7 8 #include <stddef.h> 9 #include <stdint.h> 10 11 #include "base/macros.h" 12 #include "size.h" 13 14 namespace media { 15 16 // An AcceleratedVideoDecoder is a video decoder that requires support from an 17 // external accelerator (typically a hardware accelerator) to partially offload 18 // the decode process after parsing stream headers, and performing reference 19 // frame and state management. 20 class AcceleratedVideoDecoder { 21 public: AcceleratedVideoDecoder()22 AcceleratedVideoDecoder() {} ~AcceleratedVideoDecoder()23 virtual ~AcceleratedVideoDecoder() {} 24 25 virtual void SetStream(const uint8_t* ptr, size_t size) = 0; 26 27 // Have the decoder flush its state and trigger output of all previously 28 // decoded surfaces. Return false on failure. 29 virtual bool Flush() WARN_UNUSED_RESULT = 0; 30 31 // Stop (pause) decoding, discarding all remaining inputs and outputs, 32 // but do not flush decoder state, so that playback can be resumed later, 33 // possibly from a different location. 34 // To be called during decoding. 35 virtual void Reset() = 0; 36 37 enum DecodeResult { 38 kDecodeError, // Error while decoding. 39 // TODO(posciak): unsupported streams are currently treated as error 40 // in decoding; in future it could perhaps be possible to fall back 41 // to software decoding instead. 42 // kStreamError, // Error in stream. 43 kAllocateNewSurfaces, // Need a new set of surfaces to be allocated. 44 kRanOutOfStreamData, // Need more stream data to proceed. 45 kRanOutOfSurfaces, // Waiting for the client to free up output surfaces. 46 kNeedContextUpdate, // Waiting for the client to update decoding context 47 // with data acquired from the accelerator. 48 }; 49 50 // Try to decode more of the stream, returning decoded frames asynchronously. 51 // Return when more stream is needed, when we run out of free surfaces, when 52 // we need a new set of them, or when an error occurs. 53 virtual DecodeResult Decode() WARN_UNUSED_RESULT = 0; 54 55 // Return dimensions/required number of output surfaces that client should 56 // be ready to provide for the decoder to function properly. 57 // To be used after Decode() returns kAllocateNewSurfaces. 58 virtual Size GetPicSize() const = 0; 59 virtual size_t GetRequiredNumOfPictures() const = 0; 60 61 private: 62 DISALLOW_COPY_AND_ASSIGN(AcceleratedVideoDecoder); 63 }; 64 65 } // namespace media 66 67 #endif // ACCELERATED_VIDEO_DECODER_H_ 68